摘要:
The invention relates to a method for treating a foamable plastic, according to which the plastic is converted from an initial condition with a higher density into a foamed condition with a lower density, using a gasifying agent in a foaming process. The plastic is cross-linked prior to the foaming process by means of a first cross-linking agent and during the foaming process by means of at least one second cross-linking agent.
摘要:
Disclosed is an evacuated and unevacuated microcellular foam containing an infrared attenuating agent (IAA). The evacuated foam has an average cell size of 70 micrometers or less. The unevacuated foam has an average cell size of 1.0 micrometers or less. The IAA provides a greater proportional reduction in foam thermal conductivity in these foams than in foams or larger cell size. Further disclosed is a method of using the foams.
摘要:
L'invention concerne un procédé de refroidissement rapide d'un matériau mousse poreux afin d'empêcher l'oxydation et l'autoallumage de ladite mousse. Le procédé comprend une première étape de refroidissement au cours de laquelle de l'air ambiant refroidi est aspiré à travers le bloc de mousse (1) pour refroidir, dessécher et éliminer les fumées du bloc de mousse avant de l'éventer, une seconde étape de refroidissement au cours de laquelle de l'air ambiant refroidi est aspiré à travers le bloc condensé puis redéposé dans le bloc afin de le refroidir davantage, avec des sublimés dans le bloc et une troisième étape de refroidissement au cours de laquelle de l'air ambiant est aspiré à travers le matériau mousse de manière à éliminer les fumées, la chaleur et l'humidité restantes. Le procédé de la présente invention utilise de manière avantageuse une formulation de mousse qui comprend un pourcentage accru d'eau pour effectuer un moussage adéquat du matériau tout en réduisant au minimum ou en éliminant le besoin d'incorporer des agents toxiques auxiliaires de soufflage dans la composition. De plus, la composition peut également avoir un indice TDI plus bas que celui des compositions utilisées dans des procédés classiques de refroidissement étant donné que TDI (diisocyanate de toluène) est condensé puis recyclé dans la mousse. Un appareil spécialement conçu et adapté pour mettre en oeuvre le procédé de la présente invention est également décrit.
摘要:
Polyurethane foams having a specified glass transition temperature are densified for transportation or other purposes by heating the foam to a temperature above its Tg, compressing the heated foam, and then cooling the compressed foam to a temperature below its Tg. The cooled foam remains in a densified state until re-heated to a temperature above its Tg, whereupon it re-expands to assume its original dimensions.
摘要:
Polyurethane foams having a specified glass transition temperature are densified for transportation or other purposes by heating the foam to a temperature above its Tg, compressing the heated foam, and then cooling the compressed foam to a temperature below its Tg. The cooled foam remains in a densified state until re-heated to a temperature above its Tg, whereupon it re-expands to assume its original dimensions.
摘要:
A process of producing a thermoplastic polyester series resin foamed material is disclosed, which comprises heating and further foaming a thermoplastic polyester resin foamed material having a crystallinity of not higher than 30% by bringing into contact with water or steam of at least 60°C and then heating the foamed material by bringing into contact with a heating medium other than water of at least 100°C to further foaming the foamed material. A process of producing a thermoplastic polyester series resin foamed material is also disclosed, which comprises heating and further foaming a thermoplastic polyester series resin foamed material having a crystallinity of not higher than 30% by bringing into contact with water to steam of at least 60°C, heating and further foaming the foamed material by bringing into contact with a heating medium other than water of at least 100°C, and molding the foamed material by a mold.
摘要:
A steam expanded alkenyl aromatic polymer composition (10) is provided. The polymer is mixed with a volatile blowing agent containing, as a primary blowing agent, dichlorodifluoromethane and as a secondary blowing agent, a halogenated hydrocarbon, a hydrocarbon, or an aliphatic alcohol containing from 1 to 4 carbon atoms. The secondary blowing agent has a normal atmospheric boiling point of from 0o to 100oC. The admixture of polymer and blowing agent may be expanded by steam immediately after extrusion foaming or may be expanded after aging of the composition which has been impregnated with the volatile blowing agent.